Method and apparatus for processing yarn



Aug. 4, 1970 I D. J. FISHER. JR 3,522,700

METHOD AND APPARATUS FOR PROCESSING YARN Original Filed April 22. 1966INVENTOR DANIEL J. F HER JR. w wfi i United States Patent 3,522,700METHOD AND APPAyRgTJS FOR PROCESSING R Daniel J. Fisher, Jr., NorthKingstown, R.I., assignor to Leesona Corporation, Warwick, R.l., acorporation of Massachusetts Continuation of application Ser. No.552,480, Apr. 22, 1966. This application Oct. 23, 1968, Ser. No. 770,901Int. Cl. D02g 3/22, 3/34; B65h 75/00 US. Cl. 57157 3 Claims ABSTRACT OFTHE DISCLOSURE The disclosure concerns a method of processing falsetwist yarn into a set yarn wherein the false twist yarn is wound into asoft package on a package support which comprises a hard core aroundwhich is snugly fit a sleeve of resilient foam material as, for example,polyurethane which is chosen to have a compressibility factor which isequal to the compressive force exerted by the yarn on the packagesupport when the packaged yarn is autoclaved in the course of making theset yarn.

This application is a continuation of my application No. 551,480, filedApr. 22, 1966, now abandoned.

The present invention relates to textured synthetic yarn and moreparticularly to a process and apparatus for producing such yarn.

Synthetic thermoplastic yarns are conventionally given stretch orelastic properties by being highly twisted, heat set in the twisted formand then untwisted. A process and apparatus for continuously so treatingyarn is disclosed in U.S. Pat. No. 3,152,436 issued Oct. 13, 1964 to C..T. Dudzik et al. In the apparatus disclosed in the Dudzik et al. patenta yarn feed roller is provided for drawing the strand of yarn beingtreated through a heating zone and a false twist spindle and advancingthe yarn to a winding mechanism. The winding mechanism customarily windsthe yarn at a speed slower than the speed at which the feed rolleradvances it to permit the yarn to relax or contract a predeterminedamount as it is wound.

Yarn produced by the Dudzik apparatus possesses a great amount ofstretch or elasticity, customarily being capable of stretching at least500% from its relaxed condition. For many uses this amount of stretch isundesirable, and it is customary in the art to modify such yarn byfurther heating it in a partially extended condition to remove much ofthe stretch characteristics but to leave predetermined desired bulk ortextured characteristics. When yarn produced by the apparatus disclosedin said Dudzik et al. Pat. 3,152,436 is wound by its winding mechanismin a sufficiently relaxed condition the characteristics of said yarn canbe modified by placing the packages in an autoclave or similar heatingmeans such as a hot dye bath, and heating the yarn to a temperatureslightly above the temperature at which it was set.

Stretch yarn modified in the above described manner lacks uniformitybetween the yarn on the outside of the package and yarn on the inside ofthe package. This lack of uniformity is due to the different amounts theyarn can shrink or contract as it is heated.

One object of the invention is to provide a method of processing yarnwhich comprises the steps of continuously twisting a running strand ofyarn, continuously untwisting said strand, and winding said strand intoa soft package advancing said strand towards a takeup package having auniformly compressible core at a linear speed greater than the surfacespeed of said package.

A further object of the invention is to provide a core upon which yarnmay be wound having a relative in- 3,522,700 Patented Aug. 4, 1970 ice .ing the present invention; and

FIG. 2 is an enlarged arcuate section taken through the body of thecore.

Tube 10 may be of fibrous or other suitable material. An annularintegument 12 of flexible foam material is receivable thereon,preferably by means of a snug fit, although an adhesive bond or othermode of fastening can be employed. The snug fit is desirable for ease ofremovable of the integument from the reusable tube after the settingprocess has been completed while yet preventing undue creep of theintegument across the surfaceof the tube during the winding operation.The reason for removing the integument from the tube after the settingprocess resides in the fact that flexible foam materials aresufficiently deformed by the setting process that they are not desirablyreusable. Thereupon, a fresh integument must be applied to the tubeprior to an ensuing operation again employing the flexible core. Thecomposition of the integument is desirably an open-cell flexible foammaterial such as latex rubber foam or one of a large range of foamplastic materials. A composition which produced the satisfactory resultsover the range of overfeeds curently employed for modifying yarns wasfound to be a flexible urethane foam bearing the composition number P-22and produced by the General Tire and Rubber Company. Closed cell foammaterials have also been found suitable for use in the integumentherein. However, if the package is to be subsequently dyed, for example,such closed cell integument may restrict dye penetration to all parts ofthe package.

Tube 10 is of particular value for use in taking up yarns produced onthe apparatus disclosed in said Dudzik Pat. 3,152,436 and which is to besubsequently modified by treatment in an autoclave or hot dye bath. Ithas been determined that the quality of a modified textured yarn soproduced varies in relation to the percentage of overfeed and thecompressibility of the integument. That is, an integument which is toosoft will allow too much yarn shrinkage and cause a reverse variationwherein greater stretch properties are retained by yarn located in theregion of the core than the running yarn. Oppositely, as the integumentis made harder the yarn variation exhibited approaches that of yarnwound on a conventional non-yieldable core. Then too, the lower thepercentage of overfeed, the greater must be the initial compressibilityof the integument because yarn so wound will have a comparativelygreater tendency to compress the core than yarn wound at a higherpercentage of overfeed. In like fashion, a softer integument is desiredfor the higher percentages of overfeed. When the yarn is treated in theautoclave or hot dye bath, the foam is caused to be compressed by reasonof the shinkage of the yarn. By choosing an integument having the propercompressibility, i.e., having a compressibility factor equal to orslightly less than that exerted by the shrinkage forces of the yarn asthe yarn is shrunk during subsequent processes such as dyeing orautoclaving, the yarn located next to the core of the package shrinksuniformly in the same proportion as the yarn located in regions distantfrom the core. The resulting package manifests a uniformity which washeretofore unattainable, and fabrics woven or knitted therefrom are ofsuperior quality.

An example of yarn processed in accordance with the instant invention isas follows. A polyester yarn manufactured by E. I. du Pont de Nemoursand Company, and sold under the designation Dacron 150 denier, 34filament R 10, Type 56 was processed on apparatus of the type disclosedin US. Pat. 3,152,436. The yarn was wound onto a form constituted as aconventional hard paper tube having an internal diameter of 3.25 inchesand having a wall thickness of generally .19 inch. The paper tube wascovered with a uniform layer .25 inch in thickness of flexible urethanefoam sold by the General Tire and Rubber Co. under the compound numberP-22. The finished package dimensions were 5.5 inches in width and 9inches in diameter. The package weighed about 2 pounds. The overfeedemployed was 12%. The wound package was processed in an autoclavemanufactured by the Gaston County Company. The cycle consisted of:

(a) 5 minutes of vacuum at 26 inches of mercury.

(b) 45 minutes of dry steam at 27 pounds gage pressure (c) 10 minutes ofvacuum at 26 inches of mercury.

(d) 3 minutes of exhaust.

The processed yarn was unwound and found to be uniform in its stretchproperties, shrinkage characteristics, texture, and torque anglethroughout its entire length.

Although specific practices have been set forth, and description hasbeen made of preferred embodiments constructed of preferred materials,it should be understood that various changes, modifications, additions,and substitutions may be effected by those skilled in the art withoutdeparture from these teachings, and it is directed in the appendedclaims to embrace all such variations as fall within the true spirit andscope of this invention.

Since certain changes may be made in the above apparatus withoutdeparting from the scope of the invention herein involved, it isintended that all matter contained in the above description or shown inthe accompanying drawing shall be interpreted as illustrative and not ina limiting sense.

What is claimed is:

1. The method of using a yarn core comprising a rigid central tube theouter surface of which is covered by a flexible foam material saidmethod comprising winding a false-twist textured thermoplastic yarn atan overfeed rate onto said core to form a yarn package in which saidtextured yarn is in a partially extended condition, and heating saidpackage, whereby the stretch properties of said yarn are modified withsubstantial uniformity from the center to the outside of said package.

2. The method of claim 1 wherein said foam is opencelled.

3. The method of uniformly modifying the stretch properties of asynthetic yarn which has been highly twisted, heat set in the twistedform and then untwisted by heat setting said yarn in a partiallyextended condition comprising:

advancing a strand of said yarn toward a winding mechanism at linearrate greater than the winding speed of said mechanism,

winding said yarn by said winding mechanism into a package upon a corehaving an outer surface with a uniform compressibility factorsubstantially equal to the compressive force exerted thereupon by theshinkage of said yarn during subsequent processing, and heating the yarnthus wound.

References Cited UNITED STATES PATENTS 2,982,493 5/1961 Sibille 242118.23,106,725 10/1963 Stiner et al. 242118 3,131,528 5/1964 Scragg 57157 XR3,147,579 9/1964 Michalek 57-157 XR 3,316,705 5/1967 Nava 57157 FOREIGNPATENTS 1,429,360 1/ 1966 France.

988,093 4/1965 Great Britain.

STANLEY N. GILREATH, Primary Examiner W. H. SCHROEDER, AssistantExaminer US. Cl. X.R. 28--72; 242-1182

